Number of words: 735

Remarkably, the colonies cannot survive without their Leucocoprinus fungus and the fungus is found nowhere but in these colonies. They do not do farm the precious fungus on the surface. Instead, they grow fungus in underground chambers that can reach the size of a football. In all, a single leaf-cutter nest may harbor a thousand such chambers. The smallest ants tend the fungus gardens and use antibiotic-producing bacteria to ensure their crop remains free from disease. They weed the gardens too, removing competing fungal strains, and keep it at an ideal, slightly acidic, pH. Thus the colony farms depend on three-way cooperation between ants, bacteria, and fungi.
 Thanks to the digestive powers of the fungus, the ant larvae are able to consume the otherwise unpalatable harvest of tropical forests whose leaves are laden with chemicals designed to deter browsers, such as terpenoids and alkaloids. These ants are able to grow a monoculture year after year without disaster, and they use their antibiotic so prudently that there’s no sign of the antibiotic resistance that now plagues human medicine.
As a rule, riskier jobs are left to older workers who are destined soon to perish. Examples include waste disposal and defense. If the colony is disturbed, soldiers storm out of the nest and attempt to overpower the aggressor. While we send young men to war, ants send their old ladies. Soldiers are a caste of elderly females, each with a three millimetre  wide head and well-developed mandibles. Their bite can penetrate human skin. So tenacious are their jaws that indigenous people in the Americas use them as sutures for holding the edges of wounds together.
Ant wonders do not end there. To establish new colonies, young males and females depart on a mating flight each year. A winged female ant mates with up to eight males, typically from other colonies, high in the air during a nuptial flight and stores all the accumulated sperm for the rest of her life. After the flight, all males die. The young queen digs a vertical shaft and creates a chamber at the bottom, which serves as the first of her own nests. There she deposits a fungus wad from her original colony (carried in a pouch on her body, called the in frabuccal  pocket) to start a new fungus garden, the success of which is crucial for the future of the new colony. She removes her four wings, eats them, and lays her first handful of eggs. When the first workers emerge, they begin to eat, and to tend, the fungus culture. Groomed and fed by her workers, she can lay 20 eggs per minute, 28,800 per day, and 10.5 million each year. During her lifetime, a queen can produce more than 150 million daughters.
Ant colonies have much to teach us about the secrets of cooperation and advanced social behavior. They are one of the most successful forms of life, with at least 14,000 species. They have perfected ways to divide up labor to cooperate that appears more collegial than anything we do. They developed agriculture and architecture millions of years before our ancestors had even managed to walk upright. They are able to wage war. Unlike most ant species, army ants do not construct permanent nests but forage incessantly, pouring into an Atta nest and looting it if its citizens cannot mount an adequate defense against the marauders. Ants are also able to cooperate with other species, so that their lives are knotted together in a ruthless yet highly successful struggle for survival. For example, some species tranquilize aphids with drugs to keep them docile and “milk” them with their antennae for a treat of sugary honeydew.
 In these eusocial societies, some group members surrender part or all of their personal genetic fitness to benefit fellow members other than their own direct descendants. It is the most advanced form of cooperation to be found in insects. And it works. Social insects are the most abundant of the land dwelling arthropods. Ants are perhaps the premier example, with the global mass of ants (up to 10 million billion of them, give or take) being roughly the same as the global mass of people. Even more impressive, these societies have thrived since the days of the dinosaurs. They offer an extraordinary glimpse of how cooperation can emerge from competition.
Excerpted from page 154-156  of ‘Super co-operators ’ by Martin Nowak